Bretsinclair Posted September 19, 2011 Report Share Posted September 19, 2011 Hello. I have been experiencing rough idle at start up ever since I had the car. It went away for a few months and came back recently. At first I thought it was due to starting the car too fast and not wait long enough for all the electronics to have switched on or the software of the ECU to be up and running. But now I am not sure it is related. When I start the car, from times to times the engine vibrates and the revs go up and down erratically. (illustrated in the video above video) It looks like the injection is not being made properly or something related. It goes from 500 rpm to 1500 or 2000 and comes back down. After ahwhile it stops and the engine starts running smoothly. It has 55k miles and I have had it for 11 months. It has always done that and went to a trustworthy indy garage that saw nothing wrong with the car. It looks like this happens when the car is HOT and not on cold start-up like explained in the bulletin SI B 11 02 05: 62 Engine - Rough Idle, Misfire Faults after Cold Start I have done loads of start-ups this week end to replicate the problem and it looks like the car starts better and quicker when cold... Also it seems like the car runs at higher revs than usual. When it starts it stays around 1000 for 30 seconds or so then comes back down. Although instead of settling in at around 500 rpms it revs around 700 for awhile until I start driving. Then goes back to 500 rpms. Temperature is the same as usual, petrol is the same as usual... Go figure. Let me know if someone has any more details/answers. Link to comment Share on other sites More sharing options...
NewNiceMrMe Posted September 19, 2011 Report Share Posted September 19, 2011 Is it an early car? i.e. 2004 or pre-March 2005? The engine is known to have Valvetronic related issues from the first units produced and it's a very big job to fix. If you get the message "High engine load" then that coupled with the problem going if you switch off and back on are key signals. Apart from that I've no idea what it could be. Link to comment Share on other sites More sharing options...
Bretsinclair Posted September 21, 2011 Author Report Share Posted September 21, 2011 Is it an early car? i.e. 2004 or pre-March 2005?The engine is known to have Valvetronic related issues from the first units produced and it's a very big job to fix. If you get the message "High engine load" then that coupled with the problem going if you switch off and back on are key signals. Apart from that I've no idea what it could be. Not sure, it was first registered on May 2004.... if you are talking about the Vanos I am aware that this is a big job. To be honest I had this problem 6 months ago and was told that the battery was too small for my car and thus changed it to a newer , bigger one. Problem was gone. It has started recently, and it seems to be doing it only when car is still warm. after that it seems to be working normally. When cold in the morning or evening it starts perfectly. It does seem however to be revving higher than usual i.e. it goes from 1000 to 700 instead of regular 500rpm. I then start driving and it settles back to 500rpm. I am bringing it this Thursday to my Indy garage that I trust, hoping that he'll be able to tell me good news. Link to comment Share on other sites More sharing options...
NewNiceMrMe Posted September 21, 2011 Report Share Posted September 21, 2011 No I'm not talking about Vanos - and May 2004 makes it a VERY early car. That immediately makes me suspicious that it is the well known fault. There was a recall, I'm pretty sure - you might want to ask the Indy what they can ascertain from the ECU/key - I don't know if they can see recall work on there or not. I hate to say but it won't be cheap - it never is on a 6 series. Link to comment Share on other sites More sharing options...
Bretsinclair Posted September 26, 2011 Author Report Share Posted September 26, 2011 Ok I just got my car back... my indy told me the car was fine and that it was the valve timing motor on bank 1 that was not working properly. Cleaning and reset of throttle body 8 new spark plugs Knew bank valve timing motor Total 650 GBP .... Will let you know how the car runs, finger's crossed. A Link to comment Share on other sites More sharing options...
Bretsinclair Posted October 31, 2011 Author Report Share Posted October 31, 2011 Changed the valve timing motor on bank 1 and no rough idle on start-up until last week end. Cleaning and reset of throttle body 8 new spark plugs Knew bank valve timing motor... 650£ And the problem is back... Suggestions welcome. Link to comment Share on other sites More sharing options...
Calm Chris Posted October 31, 2011 Report Share Posted October 31, 2011 Air filter? Have you tested the emissions, just to make sure the cats aren't at eol? (logic being they work better when at running temp when the heat has warmed them!) Link to comment Share on other sites More sharing options...
Bretsinclair Posted October 31, 2011 Author Report Share Posted October 31, 2011 Hi Chris, Thanks for your response, If you scroll up, you'll be able to see the video of the weird reving the car does upon start-up. It seems to be happening only when the car is still hot. Don't think it ever did it when cold... Some say it could be the valvetronic, some think it could be the battery. Once engine has settled it drives perfectly. A Link to comment Share on other sites More sharing options...
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